1 //===--- llvm/CodeGen/WasmEHFuncInfo.h --------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // Data structures for Wasm exception handling schemes. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #ifndef LLVM_CODEGEN_WASMEHFUNCINFO_H 14 #define LLVM_CODEGEN_WASMEHFUNCINFO_H 15 16 #include "llvm/ADT/DenseMap.h" 17 #include "llvm/ADT/PointerUnion.h" 18 #include "llvm/ADT/SmallPtrSet.h" 19 20 namespace llvm { 21 22 class BasicBlock; 23 class Function; 24 class MachineBasicBlock; 25 26 namespace WebAssembly { 27 enum Tag { CPP_EXCEPTION = 0, C_LONGJMP = 1 }; 28 } 29 30 using BBOrMBB = PointerUnion<const BasicBlock *, MachineBasicBlock *>; 31 32 struct WasmEHFuncInfo { 33 // When there is an entry <A, B>, if an exception is not caught by A, it 34 // should next unwind to the EH pad B. 35 DenseMap<BBOrMBB, BBOrMBB> SrcToUnwindDest; 36 DenseMap<BBOrMBB, SmallPtrSet<BBOrMBB, 4>> UnwindDestToSrcs; // reverse map 37 38 // Helper functions getUnwindDestWasmEHFuncInfo39 const BasicBlock *getUnwindDest(const BasicBlock *BB) const { 40 assert(hasUnwindDest(BB)); 41 return cast<const BasicBlock *>(SrcToUnwindDest.lookup(BB)); 42 } getUnwindSrcsWasmEHFuncInfo43 SmallPtrSet<const BasicBlock *, 4> getUnwindSrcs(const BasicBlock *BB) const { 44 assert(hasUnwindSrcs(BB)); 45 const auto &Set = UnwindDestToSrcs.lookup(BB); 46 SmallPtrSet<const BasicBlock *, 4> Ret; 47 for (const auto P : Set) 48 Ret.insert(cast<const BasicBlock *>(P)); 49 return Ret; 50 } setUnwindDestWasmEHFuncInfo51 void setUnwindDest(const BasicBlock *BB, const BasicBlock *Dest) { 52 SrcToUnwindDest[BB] = Dest; 53 UnwindDestToSrcs[Dest].insert(BB); 54 } hasUnwindDestWasmEHFuncInfo55 bool hasUnwindDest(const BasicBlock *BB) const { 56 return SrcToUnwindDest.count(BB); 57 } hasUnwindSrcsWasmEHFuncInfo58 bool hasUnwindSrcs(const BasicBlock *BB) const { 59 return UnwindDestToSrcs.count(BB); 60 } 61 getUnwindDestWasmEHFuncInfo62 MachineBasicBlock *getUnwindDest(MachineBasicBlock *MBB) const { 63 assert(hasUnwindDest(MBB)); 64 return cast<MachineBasicBlock *>(SrcToUnwindDest.lookup(MBB)); 65 } 66 SmallPtrSet<MachineBasicBlock *, 4> getUnwindSrcsWasmEHFuncInfo67 getUnwindSrcs(MachineBasicBlock *MBB) const { 68 assert(hasUnwindSrcs(MBB)); 69 const auto &Set = UnwindDestToSrcs.lookup(MBB); 70 SmallPtrSet<MachineBasicBlock *, 4> Ret; 71 for (const auto P : Set) 72 Ret.insert(cast<MachineBasicBlock *>(P)); 73 return Ret; 74 } setUnwindDestWasmEHFuncInfo75 void setUnwindDest(MachineBasicBlock *MBB, MachineBasicBlock *Dest) { 76 SrcToUnwindDest[MBB] = Dest; 77 UnwindDestToSrcs[Dest].insert(MBB); 78 } hasUnwindDestWasmEHFuncInfo79 bool hasUnwindDest(MachineBasicBlock *MBB) const { 80 return SrcToUnwindDest.count(MBB); 81 } hasUnwindSrcsWasmEHFuncInfo82 bool hasUnwindSrcs(MachineBasicBlock *MBB) const { 83 return UnwindDestToSrcs.count(MBB); 84 } 85 }; 86 87 // Analyze the IR in the given function to build WasmEHFuncInfo. 88 void calculateWasmEHInfo(const Function *F, WasmEHFuncInfo &EHInfo); 89 90 } // namespace llvm 91 92 #endif // LLVM_CODEGEN_WASMEHFUNCINFO_H 93